Dummy cartridge



19.59 Y A. N; BENSON 2,882,821

DUMMY CARTRIDGE Filed Nov. 4, 1955 I4 IO I2 II I3 INVENTOR.

K ALBIN N. BENSON BY W7 i mw, Q. w. @Wm ,M am.

ATTORNEYS United States Patent O DUMMY CARTRIDGE Albin N. Benson,Pipersville, Pa.

Application November 4, 1955, Serial No. 545,138

2 Claims. (Cl. 102-41) (Granted under Title 35, U.S. Code (1952), sec.266) The invention described herein may be manufactured and used by orfor the Government for governmental purposes without the payment of anyroyalty thereon.

This invention relates to dummy ammunition for machine guns and has foran object to prolong the life of the former for repeated usage.

Manufacturers of machine guns and auxiliary machine gun parts find itnecessary to try them out before shipment and such trials are usuallymade in part with dummy rather than with service ammunition. This dummyammunition should be of the same size and same weight as the serviceammunition in order that the trial may give the correct information. Inoperation of the larger sizes of machine guns such as the 20 mm. or the30 mm., the sudden starting and stopping of the dummy ammunition hasbeen found to impose flexural stress which distorts and loosens thesimulated cartridge case retaining the dummy projectile and renderingthe loosened dummy ammunition unfit for continued service.

According to this invention, an analysis of the stresses imposed uponsuch dummy anmiunition has revealed the cause of the cartridge casebecoming loose around the projectile and umt for service. Specifically,it has been found that an axial reinforcing rod rigidly iixed withrespect to the dummy projectile and also fixed with respect to thesimulated cartridge case reduces the tendency for the latter to becomedistorted. More particularly, this reinforcing rod has been screwthreaded into the dummy projectile and gripped by the simulatedcartridge case at a convenient distance from the dummy projectile. Inthis Way the dummy projectile and the reinforcing rod together functionas a rigid lever and their attachment to the simulated cartridge case ata distance from their connection reduces the tendency for any ilexuralmovement at their connection with the front end of the simulatedcartridge case `as a fulcrum.

The single figure of the drawing is a longitudinal cross section througha preferred embodiment of the present invention.

Patented Apr. 21, 1959 rice The usual cartridge case 10 is securedaround the rear end portion of a dummy projectile 11, made of steel andprovided with the usual rotating band 12 of gilding metal. An aluminumalloy nose 13 is screw threaded into a forward end of the dummyprojectile 11.

The size of the recess behind the threaded connection of the nose isdesigned so as to adjust the weight and balance of the dummy projectileand make these characteristics similar to those of the serviceammunition.

To reduce the likelihood of the forward end of the simulated cartridgecase 10 from spreading and becoming loose from the dummy projectile, ithas been discovered that a reinforcing rod 14 of brass is useful forthat purpose. This rod 14 has its forward end screw-threaded into therear end of the dummy projectile 11 and its rear end brazed within therear wall of the cartridge case at 15. 'Ihus the rear wall of thecartridge case and the rod 14 prevent any tendency for the dummyprojectile 11 to turn or twist about a forward end of the cartridge case10 as a fulcrurn and spread the forward end of the cartridge case. Abrass rod has been found to be better able to withstand fatigueresulting from repeated use of the dummy ammunition in trying out amachine gun. The product of this invention is intended especially forthe 20 millimeter size gun land cartridge but is not limited for onlythat size.

I claim:

l. In dummy ammunition for machine guns and comprising a simulatedcartridge case, a dummy projectile held within a forward portion of saidcase, a base ange on said case, a stii metal rod connected to andspacing said projectile and base ange, said rod being of substantiallyuniform diameter and threaded at its forward end into said dummyprojectile, said cartridge case having -therein a hole through whichsaid rod may extend, a nonrotatable connection between said rod andbase, said dummy projectile having a nose portion of aluminum adjustablysecured to said dummy projectile there being a recess in said projectilebehind said nose portion the size of said recess controlling the weightand balance of said ammunition.

2. Dummy ammunition according to claim 1, said stiff metal rod being ofbrass, wherein said ammunition may better withstand fatigue resultingfrom repeated use.

References Cited in the le of this patent UNITED STATES PATENTS1,049,419 Sweet Ian. 7, 1913 1,256,255 Porter Feb. 12, 1918 2,342,549 LeGore et al Feb. 22, 1944

